Cooling systems, of the water cooling type, conventionally include a heat exchanger or radiator, in which the water which has been heated on contact with the engine circulates. The radiator is designed so as to have a maximum surface in contact with the air, and it is usually arranged to be perpendicular to the air flow path, either at the front, or at the rear of the vehicle. Generally of a rectangular shape, these conventional radiators constitute a resistance to the flow of air around the moving vehicle, which has a negative effect upon the drag coefficient (or Cx) and, consequently, the performance of the latter. For automobiles with an electric motor, it is particularly important to reduce to the minimum any energy loss as these limit considerably the maximum autonomy of the vehicles. Obtaining a very small Cx is a necessity for vehicles driven by an electric motor and intended to be able to reach speeds in the order of 100 km per hour. It is also highly desirable for the weight of the batteries, which store the basic energy, to be kept to a value as low as possible. The batteries constitute a non negligible part of the total weight of electrically controlled vehicles.